Distributing valve for steam engines



March 25, 1924. 1,487,930

A. FORSTER DISTRIBUTING VALVE FOR STEAM ENGINES Filed Oct. 11, 192] 3 Sheets-Sheet 1 1 l I g W 1; V I

| I I I I I I I I II] March 25, 1924. 1,487,930

A. FORSTER DISTRIBUTING VALVE FOR STEAM ENGINES Filed Oct. 11, 1921 3 Sheets-Sheet 2 V W N/A/ March 25, 1924. 1,487,930

A. FORSTER DISTRIBUTING VALVE FOR STEAM ENGINES Filed Oct. 11, 1921 3 Sheets-Sheet 3 Patented ar. 25, H924.-

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ANDREW EOBS'IER, OF OOWES, ISLE OF TIGHT, ENGLAND, ASSIGNOR 'IO J. SAMUEL WHITE 6: COMPANY LIMITED, 01? EA$T C'OWES, ISLE OF WIGHT, ENGLAND, A GUI-15.-

PANY OF GREAT BRITAIN.

DISTRIBUTING VALVE FOR STEAM ENGINES.

Application filed October 11, 1921.

To all whom it may concern:

Be it known that 1, ANDREW Fonsrnn, a subject of the King of England, and residing at ,Cowes, Isle of Wight, England, have 5 invented certain new and useful Improvements in Distributing Valves for Steam Engines, of which the following is a specification.

This invention relates to distributing valves of the compound type for steam engines and has particular reference to valves which comprise a main valve with a curved face adapted to reciprocate over a similarly curved chest face, and an auxiliary valve working upon or in the main valve in a path at right angles to that of the main valve.

In valves of this type the main valve reciprocates after the manner of a shuttle, thus controlling the supply ofsteam to the engine cylinder, the auxiliary valve controlling the supply of steam to the main valve and cooperating with the latter in controlling the main steam ports.

As at present made the curved port faces are subjected to excessive wear since the back or surface of the main valve remote from the main ports is always exposed to the full steam pressure. Hence the piston-like ends of the main valve soon fail to fit their cylinders and although floating bells have been proposed to overcome this drawback the construction is complicated and the onesided pressure on the valve remains.

The object of this invention is to provide a valve of the above type in which all the moving parts are balanced thus reducing the wear and distortion due to unequal pressure. A further object of this invention is to pro vide a valve which can be moved by hand if desired prior to the engine being started or while it is in operation and to furnish a positive indicator showing the position of the valves at any point in the strokeof the en ne. According to this invention a balanced reciprocating steam-actuated main valve carries a balanced auxiliary valve within it, the axes of the two valves being at right angles and the auxiliary valve being adapted both to reciprocate within the main valve and to oscillate.

In the preferred construction the main valve is of the shuttle type and comprises an approximately hollow cylindrical member Serial .No. 507,090.

having apiston face at either end and provided with ports which control the main steam ports formed in a cylindrical bore in the steam chest within which the main valve is reciprocated. Formed within the main valve at right angles to its longitudinal axis is a ported cylindrical bore within which works the auxiliary valve. The auxiliary valve comprises a hollow ported cylindrical member which is mechanically reciprocated within its bore in the main valve and is also oscillated about its own axis by the reciprocation of the main valve. The auxiliary valve controls the supply of steam which effects the reciprocation of the main valve and cooperates with the main valve in controlling the admission of steam to the main ports. As the live steam first enters the interior of the cylindrical auxiliary valve and thence passes to the interior of the cylindrical main valve, it will be seen that both these valves are balanced and not subject to unequal pressure and consequent wear, while further, the manufacture of the steam chest and its valve is greatly simplified and its assembly facilitated.

Formed in the main valve, preferably opposite the ports which cooperate with the main ports in the chest face, are supplement-- ary ports through which live steam can be admitted into the interior of the main valve when by-pass valves mounted on the exterior of the steam chest are opened.

These valves are opened, as for instance when starting up, and when opened, although the auxiliary valve cuts ofi steam at about three-quarter stroke, full pressure steamwill flow from the interior of the main valve through the main ports into the engine cylinder, to complete the stroke.

The accompanying drawings show by way of example one construction of valve according to this invention, this arrangement being particularly suitable for application to a marine auxiliary engine. In these drawings,

Figure 1 is a transverse section through the valve chest showing the operating link, and the auxiliary valve in central vertical section.

Figure 2 is a longitudinal section taken on the line 22 of Fig. 1 showing the main shuttle valve in one extreme position.

Figure 3 is a similar view showing the valve in the other extreme position, exterior pogtions of the mechanism being omitted, an

Figure 4 is a perspective view, on an enlarged scale, of the auxiliary or pilot valve.

Fig. 5 is an elevation of a conventional engine with the valve and operating mechanism.

' The steam distributing chest is provided with a cylindrical bore havin end plates A constituting a closed cylin er A. Oommunicating with the cylinder so 'formed'is a port B leading to the exhaust and ports (1 C communicating respectively with the two ends of the engine cylinder in the usual manner. Working within the cylinder A is a hollow cylindrical valve E having a piston face at either end and adapted to reciprocate after the manner of a shuttle. This cylindrical valve E constitutes the main valve and is provided with two ports D D which communicate with the interior of the valve, a recess D being formed along the centre of the valve whereby either of the steam ports 0 C may be placed in communication with the exhaust port B after the manner of an ordinary slide valve.

Formed within the main valve E at right angles to the longitudinal axis thereof is a cylindrical bore or housing F provided with two ports F F 2 through which steam is admitted'to the interior of the main valve and also having two small ports G G which communicate with passages E E respectively leading through the piston face at-each end of the main valve E into the cylindrical chamber A in which this valvereciprocates. An exhaust port G leading to the ports B,

C, C in the chest face is formed in the wall formed in the transverse bore.

The supply of steam to effect this reciprocation of the main valve E is controlled by the auxiliary valve which comprises a hollow cylindrical member H into the interior of which live steam flows constantly through openings H the valve being adapted to be reciprocated within the bore F of the main valve in a path at right angles to the main valve and the auxiliary valve being further adapted to oscillate about its own axis when the main valve reciprocates. V V

The auxiliary valve H performs two functions-e-it controls the supply of steam to effect the reciprocation of the main valve E the supply'of live steamto and also controls the supply of live steam to the interior of the main valve thus cooperating with the main valve'in controlling the engine cylinder.

To perform its first function the face of the auxiliary valve adjacent the small ports G G in the main valve is recessed as: at J and the ends thereof are also recessed as at J so that as the valve H moves within its cylinder F it admits live steam to one of the ports G G and places the other in communication with the exhaust through the port G The recess J is so shaped and dimensioned (see Figure 4) to allow for the oscillating movement of the valve H as it reciprocates. 7

To control the supply of steam to the main ports G C in the chest face, the auxiliavalve H is provided with two ports K I 1 adapted to open or close the corresponding ports F adapted to open or close the corresponding po-rts F F respectively formed in the bore F and communicating through the interior of the main valve with the main ports D D formed therein. The arrangement is such that the ports K and K are only open for the passage ofsteam to the interior of the main piston valve when their respective ports C and C are open. Thus,

when either of the ports C orC- is closed its respective port K or K is also closed so that no pressure exists within. that end of the main piston valve. 7

The auxiliary valve H is reciprocated mechanically, a rod L by which this reciprocation is imparted being disposed eccentric to the axis. of the auxiliary valve. At its lower end the auxiliary valve is provided with a stem H bored transversely to,

the axis of the valve and adapted to carry the free end of a lever L whose other end is keyed to the valve-actuating rod L, the arrangement being such thatwhen the-:main valve reciprocates, both theauxiliary valve H and its actuating rod L are caused to oscillate, the free end of the lever L sliding in the bore of the valve stem H as the valve oscillates. The actuating rod L is suitably mounted or constructed so as .to turn about its own axis as well as to reciprocate and keyed to aportion of the rod which extends outside the steam chest is a short handle or lever M by which the rod can be manually operated, this lever also serving as a positive means for indicating the position 'ofthe pilot valve and therefore of the main valve within its bore.

The operation of the valve is as follows sionv ports in the transverse bore F.- -Further movement of the auxiliary valve H admits steam to the end 2 of the main valve cylinder through'the conduit E and places munication with the exhaust port B through the corresponding small conduit E 7 The shuttle or main valve E is thus reciprocated being thrown over to the end 1 of the valve chest as shown inFig'ure 2, simultaneously oscillating the auxiliary valveH which therefore opens the admission port F in the transverse bore supplying the control of live steam, to thebottom of the engine cylinder and simultaneously placing the top of the engine cylinder in communication with the exhaust B. On. the reverse-stroke (shown in Figure 3.) the auxiliaryvalveand the main shuttle valve are. operated in;

a similar manner, cutting ofl steam to the bottom of the engine: pistonthrough the opposite port F in the transversebore at about three-quarter stroke.

For starting up where it is necessary to supply full pressure steam for the entire stroke, by-pass valves communicating with the opposite side of the main valve cylinder to the'exhaust port 1B and admission ports C C are opened, these valves, which are indicated at N when opened serving tosupply full pressure steam to the interior of the main valve through ports N formed in the face of the valve adjacent to the by-pass open ings. It is thus possible for full pressure steam to enter the engine cylinder throughout an entire stroke after the normal supply of full pressure steam has been cut off by the movement Within the transverse bor F of the auxiliary valve H.

The rod L by means of which the auxiliary valve is moved receives its movement through a lever O operated as shown by the main piston rod P and the lever M keyed to the rod L not only enables the auxiliary valve to be reciprocated by hand so that at any time before or during the operation of the engine the free movement of the valve can be adjusted, but further by rocking this hand lever the main valve can also be reciprocated. It is thus possible at any time to operate either of the valves manually and further by observing the lever M when the engine is in operation a posi tive indicator is provided showing at any moment the position which either of the valves occupies.

It will be appreciated that a steam distributing valve made in accordance with this invention can be easily constructed since both main and auxiliary valves can be formed almost exclusively by turning operations. Further the construction of the steam chest is simplified and only one stufiing box is required namely that through which the auxiliary valve actuating rod passes.

It is to be understood that the constructional details may be varied considerably without departing from this invention and s that the actuating mechanism employed will the end 1 of the main-valve cylinder in comvary in accordance with the type of engine to which the valve is applied.

What I claim as my invention and desire to secure by Letters Patent is 1. In a distributing valve for steam engines the combination with a steam chest having steam and exhaust ports therein, a balanced main piston valve adapted to reciprocate within the chamber and control said ports, a balanced auxiliary valve mounted within the main valve and adapted to reciprocate at right angles to the path of the main valve and also to oscillate about its own axis so as to control the supply of steam to the main valve, and means for reciprocating the auxiliary valve as set forth.

2. In a distributing valve for steam engines the combination of a chamber having steam and exhaust ports therein communicating with the engine cylinder, a hollow ported cylindrical main piston valve adapted to be reciprocated by steam within the chamber, a ported cylindrical chamber formed within the main valve, a hollow cylindrical ported auxiliary valve controlling the supply of steam to the main valve mounted in said cylindrical chamber and adapted to oscillate about its own axis under the reciprocating movement of the main valve, and means for reciprocating the auxiliary valve within the main valve in a path at right angles to that of the main valve as set forth.

3. In a distributing valve for steam engines the combination of a steam chest having a cylindrical bore therein communicating with the main cylinder ports, a substantially hollow ported cylindrical steam-actuated piston valve adapted to reciprocate therein, said piston valve also having a ported transverse cylindrical bore formed in it, a hollow auxiliary valve mounted in said transverse bore and adapted to control the supply of steam to the piston valve and main cylinder ports and means for reciprocating said auxiliary valve at right angles to the path of the piston valve, said means permitting the auxiliary valve to oscillate a an actuating rod connected to the auxiliary J valve mounted in said transverse bore an d adapted to control the supply of steam to the piston valve and main cylinder ports,

valve extending through the steam chest and means for reciprocating said rod, saidmeans permitting the auxiliary valve to oscillate about its OWII'ZLXIS under the re-. clprocatlon of the main valve as -set iorth.

5. In a distributing valve for stealmen gines the combination of a steam chest havmounted in said transverse bore the piston valve and main cylinder ports; a

reciprocating rod connected to the auxiliar Valve extendlng through the steam chest,- an actuating lever on said rod, and addrtional means for automatically reciprocating said rod, the lever further constituting an indicator of the relative position oftheauxiliary and' ist'o'n valves within their casi I a 6 In -a distributing valve forsteam engines the combination of Y a steam chest hav-' ing 'acylindrical bore thereincommunicat ing asset fort ing' with the main -cylind'e'r f ports,- a substantially hollow ported cylindrical stea1'n'-; actuated pi ston-valve adapted to reciprocate thereinysaid pistonva1ve"- also havinga ported-transverse cylindrical bore formedmounted 'in gsaid transverse bore and-having openings through which steamis constantlyadmitted' to the' 'interior' of said auxiliary valve; and means ifor reciprocating the *aux-.

iliary valvewithin: its boref' at' right angles to-the pathfof the piston valve so as to con trol the "supply of steam toi the interior of the piston "-valve and throughthe" ports" therein to the main cylinder ports, said means also' permittingfthe auxiliary valve 50 reciprocation of a the mainvalveas set to oscillate about its oWn axis unde a the forths V In testim0ny whereof- I have name to this specification'.-

ANDREWI FORSTER? signed my 

